(1) Field of the Invention
The present invention pertains to an apparatus and a method of controlling the apparatus to assemble and inspect formed tubing assemblies. More specifically, the present invention pertains to a coordinate table and a plurality of robotic fixtures mounted for movement on the table. The robotic fixtures are controlled to move to predetermined positions on the table and tubing holders on the robotic fixtures are controlled to receive portions of a bent length of metal tubing to inspect and assemble the portions of the tubing.
(2) Description of the Related Art
Formed or bent lengths of metal tubing are used in a variety of manufactured products for conveying fluids such as hydraulic fluid and pressurized air. Formed metal tubing is used in the manufacture of aircraft, ships, and land vehicles, to name only a few examples.
In manufacturing procedures involving formed metal tubing, it is often necessary to first inspect the tubing to insure that bends formed in the tubing length have been bent at the correct angles, and to ensure that portions of the tubing length have the correct dimensions. The inspections are performed on the tubing to ensure that the tubing will fit properly in its intended position in the manufactured product.
It is currently very time-consuming and expensive to assemble and inspect hydraulic, air and other tubing used in the manufacture of products such as aircraft, ships, and land vehicles. Tubing is typically assembled for welding and inspection using manual methods that employ either dedicated holding fixtures or adjustable holding fixtures. Adjustment data for the adjustable holding fixtures is provided by dedicated drawings for the particular tubing part, or by digital data for the particular tubing part that is recorded in a coordinate measurement machine.
In the use of dedicated fixtures in the assembly and inspection of tubing, a set of fixtures is specifically designed for each particular tubing part. A part number of the tubing part identifies which set of fixtures is used to assemble and inspect the tubing part. The tubing part number is used to retrieve the specific set of fixtures from a storage facility where the dedicated fixtures are kept. The set of fixtures are manually retrieved from the storage facility and then are manually assembled relative to each other. The particular tubing part is then mounted on the assembled fixtures for inspection of the part. In the inspection of the tubing part the bent angles of the part and the dimensions of portions of the part are checked by mounting the part on the dedicated fixtures.
The assembly and inspection of tubing using dedicated fixtures requires a considerable amount of time to assemble the set of fixtures. For a manufacturing facility that makes use of a number of different tubing parts, a set of fixtures is specifically designed for each tubing part and these sets of fixtures are kept in inventory until needed. This results in thousands of sets of fixtures being stored in inventory. These thousands of sets of fixtures must also be periodically inspected to ensure that the use of the fixtures over time has not altered the configurations and dimensions of the fixtures. Thus, the maintenance of the dedicated fixtures is also very time-consuming and costly.
The use of adjustable fixtures with dedicated drawings requires that a set of adjustable fixtures be manually retrieved from inventory and manually adjusted for each tubing part to be assembled and inspected. The adjusted fixtures are manually positioned on a mylar drawing at specific positions on the drawing for the particular tubing part to be assembled and inspected. This procedure requires the storage and maintenance of a large number of adjustable fixtures and dedicated drawings, each corresponding to a particular tubing part. The drawings, as well as the adjustable fixtures, are manually retrieved from storage when needed. This procedure is also very time-consuming and costly.
The use of adjustable fixtures with a coordinate measurement machine eliminates the need for storing thousands of drawings for the tubing parts, but still requires manual adjustment and positioning of the adjustable fixtures for the assembly and inspection of the tubing parts. This procedure is also time-consuming and costly.